Air cooled blower-type cleaner



' Filed June 9, 1955 Sept. 15, 1959 SCHUELER ETAL 2,904,260

AIR COOLED BLOWER-TYPE CLEANER 2 Sheets-Sheet l 1.. B. SCHUELER ET AL2,904,260

AIR COOLED BLOWER-TYPE CLEANER Sept" 15, 1959 2 Sheets-Sheet 2 FiledJune 9, 1955 .r m3 W m4; m ma wag fl 2 5 5W 0 Unite AIR COOLEDBLOWER-TYPE CLEANER The..present invention realtes to blower-typecleaning apparatus, and particularly to improvements in soot blowersofthe type. intendedfor. installation in high temperature zones offurnaces and the like.

An important object of the invention is to provide an improvedsootblower equipped with cooling means constructed .and. arranged in .suchmanner. thattheblower nozzle and adjacent parts may be installed in hightemperature zones, as, for example, in the water walls of largeindustrial boilers, and will endure for long periods ofQtime when soinstalled without the necessity for retracting the nozzle duringintervals when blowing medium isnot flowing therethrough.

Arelated object is to provide such a construction which is of simple.and inexpensive character, which is compact andflightinweight, whichinvolves no special or. complicated moving parts, which is not apt tobecome clogged, which has a longlife, and which requires a minimum ofattention and servicing.

In the past it has not been found practical to construct theblower-tubes and nozzles of soot blowersintended for such hightemperature installations of a material which is capable ofwithstandingthe heat-during the periods when theunit is not being cooled by theprojection of theblowing medium therethrough, and it has accordinglybecome universal practice to employ retractable soot blowers in. suchinstallations. Previous efiorts to utilize a cooling medium such as airhave. not beensuccessful for several reasons, among which may bementioned the high radiant heat impingement, and the difliculty involvedin the provision of a shielding screen of cooling air. In accordancewith the present'invention the exposed portion of the nozzle is coveredby a stainless steel shroud which is spaced from the blower tube.Cooling air is caused to flow through the shroud, between the shroud andthe blower tube and outwardly into the boiler through an opening whichsubstantially surrounds the nozzle. A substantial proportion of theradiant energy is reflected by the stainless steel shroud, while theremaining extraction of heat is eliected by the cooling air.

Other objects and advantages of the invention will become apparent uponconsideration of the present disclosure in its entirety.

In the drawing:

Figure 1 is a vertical sectional elevational view through a portion ofaiurnace wall, showing a soot blower constructed and installed inaccordance with our invention;

Fig. 2 is a longitudinal central sectional view, on a larger scale, ofthe blower nozzle assembly;

Figs. 3 and 4 are cross-sectional views taken substantially on the lines33 and 4-4 respectively of Fig. 2; and

Fig. 5 is a horizontal sectional plan view taken substantially on theline 5--5 of Fig. l, and looking in the direction of the arrows.

Referring now to the drawing, reference character designates the wall ofa boiler setting, the details of States Patent 2,904,260 Patented Sept.15, 1959 2 which are not illustrated, since they form .no partof. ourpresent invention, althougha water wall section is illus trated, astypifying a high temperature regionifor which our invention is suitable.Water wall tubes-as 12sextend vertically inside the wall, which is alsoprovided .with an internalpocket in-the areaofthe opening 14: fortheblower assembly, the pocketbeinglined by-ametalsup port plate 15covered'on the inside of the furnace/by; refractory cement as 16; Thesupporting plate carries on its-outer surface amounting plate 18 towhich a sleeve 20 is. bolted or. otherwise attached in a positionconcentrically surrounding, and, projecting-outwardly from the blowertube opening19rin the plates 15,.18.. The water. wall tubes in linewiththe opening 19 are bent laterally to provide clearance for theblower, as shown inFigs. 1. and 5,, The construction and arrangementofthese parts are.essentially conventional, andwill require no detaileddescription. The blower driving unitis illustrated in outline only, andis generally. designated 22. The details of construction of the blowerdriving head arealso-subject to variation and form in themselves no part.of our present invention.

The drivinghead is equipped with a. driving motor 24 which when theblower is in operation is arranged to rotate the nozzletube 30.. The,driving head is of the type wherein. the blowing fluid is deliveredthrough the head, to which the fluid is supplied through a suitablesupplytube26, the. delivery of the blowing mediumfrom the headbeingcontrolled by a valve (not. shown) containedin the head andwhich isoperatedby and in response. to rotation-of the driving mechanism.Whenthe. valve is open, the blowing medium is conductedfrom theheadthrougha tube 2.8.v The, tube 28 is drivable by the head, and.carries rigidly secured thereto the nozzle block tube.30,,which,.asshown at 32, may.be terminally welded to the-tube28 to forma coaxialextension thereof.

The endoflthenozzleblockv tube 30 projects into the furnaceand-is closedexcept for the discharge opening 33 defined by the nozzle ring 34, whichis welded. as at 35 in a suitable opening in the block tube. The. nozzleblocktube carries upon itsexposed enda caplike shroud member, 36 {largenin ,alLdimensions thant the block, tube, so that its walls are spacedoutwardly from 'those of the block tube, the shroud,extendingentirelyaround the side andend walls-of the block tube which would otherwise bedirectly exposed to the heat within the furnace, except for the smallarea represented by the opening 38 which is formed in the shroud in aposition substantially concentric with the nozzle member 34. The opening38 is somewhat larger than the nozzle member 34, to permit air to bedischarged from the shroud between the shroud and nozzle ring, as wellas to permit the discharge of the blowing medium. The rear portion 40 ofthe shroud is substantially cylindrical and is open, being held inconcentrically out-spaced relation with respect to the block tube 30 bysuitable peripherally spaced welded lug portions 42.

A cooling air supply tube 44 extends over the rear extremity 40 of theshroud 36, the shroud being rotatable with the block tube in the outerend of the tube 44. Tube 44 extends rearwardly over the block tube 30and feed tube 28 to a manifold 45 which encircles the feed tube 2 8 at aposition between the driving head and the furnace wall. The interior ofthe tube 44, which is substantially larger in diameter than the tubes 28and 30, communicates with the interior of the manifold 45 which is inturn in communication with a cooling air supply pipe 46. The spacedconcentric positioning of the tubes 28, 30, 44 is also maintained byspacing lugs '48 which are secured to the tube 28 as by welding androtate within the tube 44.

The shroud 36 is formed of relatively light gauge stainless steel and itis only secured in the area of the three locating lugs 42. The shroud isthus free to flex under heat-induced stresses. The highly reflectivesurface of the stainless steel also reflects a substantial proportion ofthe radiant energy impinging thereon, reducing heat transmission to theblock tube 30, which may be formed of ordinary mild steel. The heattransmission is also reduced by cooling air supplied through the pipe46, manifold 45 and conduit 44 to the interior of the shroud, The air isguided over the entire interior of the shroud before being dischargedthrough the opening 38. p

The cooling air supply may be derived from the air employed to createpressure within the boiler, where the boiler is of the now commonly usedpositive pressure type, and the air flow is maintained throughout theentire time when the blower is not operating. This cooling air for theblower constitutes one of the means for pres surizing the interior ofthe furnace. It will be observed that the only area where radiant heatcan impinge upon the block tube 30 and nozzle ring 34, is directlybeneath the opening 38, and that in this area the concentration ofcooling air is the greatest, so that the wiping effect of the air uponthese regions is greater than in the other areas inside the shroud andis effective to sufliciently cool these parts despite the impingement ofradiant heat thereupon through the opening.

The stainless steel from which the shroud is formed has a highlyreflective outer surface and may be so thin as to be easily distortabledue to heat induced stresses, as indicated, and would not be stiffenough to support itself and to serve as the nozzle block. Thus itimposes very little weight load on the nozzle block and does notsubstantially increase the bearing loads or the tendency of the block tosag.

While it will be apparent that the preferred embodiment of the inventionherein described is well calculated to fulfill the objects andadvantages first above stated, it will be appreciated that the inventionis susceptible to variation, modification and change without departingfrom the fair meaning and proper scope of the appended claims.

We claim:

1. In a soot blower construction, in combination with a relatively rigidblower tube haing a cantilever outer end portion from which blowingmedium is adapted to be discharged into a high heat zone and having anozzle orifice portion in said end portion for discharging the 4 blowingmedium, a protective shroud entirely supported and carried by, andspacedly encircling, said outer end portion of the blower tube, andhaving a discharge opening substantially aligned with but larger thanthe nozzle orifice, securing means engaging the tube and the shroud atspaced localized areas and forming the entire support for the shroud andsecuring the shroud to the tube in surrounding but outspaced relationthereto, the shroud being formed of relatively thin gauge, flexible,reflective metal, and having an open rear end, substantiallyunobstructed cooling fluid passage space being left from the open rearend of the shroud to said discharge opening between said tube and shroudand past said securing means, and supply means operativelyinterconnected with said open rear end of the shroud for supplying acooling fluid to the interior of the shroud outside the tube fordischarge through said shroud and outwardly through said opening in theregion of said orifice, whereby the shroud reflects heat which wouldotherwise impinge upon said blower tube and serves to conduct coolingfluid supplied by said supply means along and in contact with both theshroud and the nozzle tube, and whereby the shroud may move with theblower tube, during any movement of the latter, due to being carriedthereby, and may distort independently of the blower tube in the areasbetween said securing means.

2. A construction as defined in claim 1 wherein said blower tube andshroud have substantially cylindrical spaced side walls andsubstantially closed spaced outer ends, the shroud having an open rearend which is substantially concentric with the tube, but being otherwisesubstantially impervious except in the area of said opening, said blowertube being rotatable, and supply means comprising a non-rotatable feedtube interfitted with the open rear end of said shroud and extendingrearwardly spacedly around said blower tube.

References Cited in the file of this patent UNITED STATES PATENTS1,809,221 Snow et al. June 9, 1931 1,978,686 Moses Oct. 30, 19342,022,513 Macchi Nov. 26, 1935 2,052,747 Bishop Sept. 1, 1936 2,192,215Williams Mar. 5, 1940 FOREIGN PATENTS 286,058 Italy May 30, 1931

